After a long pestering campaign, nine-year-old Anna and her younger brother Tom finally get a pair of hamsters, but when the pets are found mysteriously dead, the siblings and neighbor Suzanne launch an investigation throughout their neighborhood.

Suzanne is delighted when her Great-Aunt Deidra leaves her Newfoundland, Beatrice, to Suzanne's mother, but Beatrice is old, slow, and has serious stomach issues which Suzanne and Anna must try to fix before Dad sends another dog away.